New vehicles must pass emission standards before being released for sale, which can include testing for nitrogen oxides, hydrocarbons, and carbon monoxide. The emission standards of these three primary substances are continually being lowered and the technology available to achieve the low tailpipe emissions are becoming more complex and costly to implement. Unfortunately, although a newly designed vehicle may pass the emissions criteria, but during service, deposits may build up on the emission control devices, sensors, intake valves, exhaust valves, fuel injectors, and combustion chamber. Such deposits can significantly reduce the ability of an emissions reduction system to reduce tailpipe emissions as designed.